REFERENCES
- Anderson , F. W. and Fuller , K. R. 1974 . Rings and Categories of Modules New York : Springer-Verlag .
- McConnell , J. C. and Robson , J. C. 1988 . Noncommutative Noetherian Rings New York : John Wiley & Sons .
- Rotman , J. J. 1979 . An Introduction to Homological Algebra New York : Academic Press .